How representative is global terrestrial wind speed from in-situ observations?

2021 ◽  
Author(s):  
Lihong Zhou ◽  
Cesar Azorin-Molina ◽  
Zhenzhong Zeng
Keyword(s):  
Wind Speed ◽  
Thermal Response ◽  
Global Scale ◽  
Climatic Conditions ◽  
Long Term Trends ◽  
In Situ Observations ◽  
Wind Energy Resources

<p>Since long-term in-situ observations over land reflect to some extent the climatic conditions of the area where they are located, observed wind speed are used for many applications, e.g.: to estimate wind energy resources, to quantify the role of winds on evapotranspiration rates, or to assess the thermal response of lakes; among many others. However, it is not well-known whether site-specific station averages are representative of wind speed conditions in the corresponding areas; in fact, few studies have explored this so far. Here, we will investigate wind speed data from observation stations and reanalysis products. By comparing the relationships of the magnitude, inter-annual variability, and long-term trends in these two datasets at various spatiotemporal resolutions, e.g., 3⁰×3⁰, 5⁰×5⁰, continental and global scale, etc., we will better understand the representativeness of wind speed changes at in-situ stations in different regions. This study will help to further reveal the uncertainties in the representativeness of studies using station-based wind speed observations.</p>

scholarly journals Traffic restrictions in Beijing during the Sino-African Summit 2006: aerosol size distribution and visibility compared to long-term in situ observations

2008 ◽  
Vol 8 (4) ◽  
pp. 12971-12998 ◽  
Author(s):  
Y. F. Cheng ◽  
J. Heintzenberg ◽  
B. Wehner ◽  
Z. J. Wu ◽  
M. Hu ◽  
...  
Keyword(s):  
Wind Speed ◽  
Fine Particles ◽  
Ultrafine Particle ◽  
Weather Conditions ◽  
Particle Formation ◽  
Control Measures ◽  
Aerosol Size Distribution ◽  
In Situ Observations

Abstract. Based on the long-term in-situ observations of aerosol particle number size distributions and meteorological parameters, the traffic restriction measures during the Sino-African Summit (4–6 November 2006) in Beijing, China have been found to be remarkably efficient in reducing the number concentration of aerosol particles, in particular Aitken and accumulation mode particles, and in improving the visibility. The influence of traffic restriction in Beijing on the particle concentrations differed for different particle sizes. More significant effects on fine particles with diameters ranging from 40 to 800 nm have been found. Based on statistical analysis of long-term observation, under comparable weather conditions, the source strength of the particles in Aitken and accumulation modes seemingly was reduced by 40–60% when the traffic restrictions were in place. It may be mainly due to the reduction of secondary particle formation. Our size-dependent aerosol data also indicate that measures led to reductions in particulate air pollution in the optically most important diameter range, whereas further vehicle control measures may lead to an increase in ultrafine particle formation from the gas phase if the condensational sink further decreased. Assuming that there were no traffic restrictions and with normal levels of the vehicle emissions, the visibilities during the Summit would have been lower by about 50%. The importance of the restrictions is highest when the wind speed is lower than 3 m s−1. The fact that over 95% cases with visual range lower than 5 km during 2004 to 2007 occurred when the local wind speed was lower than 3 m s−1 may suggest that future traffic restrictions will lead to significant improvements of visibility in Beijing.

scholarly journals Traffic restrictions in Beijing during the Sino-African Summit 2006: aerosol size distribution and visibility compared to long-term in situ observations

2008 ◽  
Vol 8 (24) ◽  
pp. 7583-7594 ◽  
Author(s):  
Y. F. Cheng ◽  
J. Heintzenberg ◽  
B. Wehner ◽  
Z. J. Wu ◽  
H. Su ◽  
...  
Keyword(s):  
Wind Speed ◽  
Traffic Control ◽  
Fine Particles ◽  
Ultrafine Particle ◽  
Weather Conditions ◽  
Aerosol Size Distribution ◽  
Wind Speeds ◽  
In Situ Observations

Abstract. Based on the long-term in-situ observations of aerosol particle number size distributions and meteorological parameters, the measures of traffic restriction during the Sino-African Summit (4–6 November 2006) in Beijing, China have been found to be efficient in reducing the number concentration of aerosol particles, in particular Aitken and accumulation mode particles, and in improving the visibility when local emissions dominated. The influence of traffic restrictions on the particle concentrations differed for different particle sizes. More significant effects on fine particles with diameters ranging from 40 to 500 nm have been found. Based on statistical analysis of long-term observations, under comparable weather conditions, the number concentrations of the particles in Aitken and accumulation modes seemingly were reduced by 20–60% when the traffic restrictions were in place. This change may be mainly due to the reduction of secondary particle contributions. However, it is worth to notice that the reduction of 60% might overestimate the effect of the measures of traffic control, due to the inherent data shortage with very high wind speeds in the comparison data population. Our size-dependent aerosol data also indicate that measures led to reductions in particulate air pollution in the optically most important diameter range, whereas further vehicle restriction measures might lead to an increase in ultrafine particle formation if the condensational sink further decreased. Assuming that there were no traffic restrictions and with normal levels of the vehicle emissions, the visibilities during the Summit would have been lower by about 20–45%. The fact that over 95% cases with visibility range lower than 5 km during 2004 to 2007 occurred when the local wind speed was lower than 3 m s−1 may suggest that the importance of the emission restrictions is highest when the wind speed is lower than 3 m s−1, concerning the improvement of serious low visibility situations in Beijing.

Global Distribution of the Solar Wind Speed Reconstructed from Improved Tomographic Analysis of Interplanetary Scintillation Observations between 1985 and 2019

2021 ◽  
Vol 922 (1) ◽  
pp. 73
Author(s):  
Munetoshi Tokumaru ◽  
Ken’ichi Fujiki ◽  
Masayoshi Kojima ◽  
Kazumasa Iwai
Keyword(s):  
Solar Wind ◽  
Wind Speed ◽  
Power Index ◽  
Solar Wind Speed ◽  
Global Distribution ◽  
Interplanetary Scintillation ◽  
Wind Speeds ◽  
In Situ Observations

Abstract Computer-assisted tomography (CAT) for interplanetary scintillation (IPS) observations enables the determination of the global distribution of solar wind speed. We compared solar wind speeds derived from the CAT analysis of IPS observations between 1985 and 2019 with in situ observations conducted by the near-Earth and Ulysses spacecraft. From this comparison, we found that solar wind speeds from the IPS observations for 2009–2019 were systematically higher than the in situ observations, whereas those for the period until 2008 were in good agreement with the in situ observations. Further, we found that the discrepancy between IPS and the in situ observations is improved by changing the power index of the empirical relation between the solar wind speed and density fluctuations. The CAT analysis using an optimal value for the power index determined from the comparison between IPS and in situ observations revealed long-term variations in the solar wind speed distribution over three cycles, leading to a better understanding of the time-varying global heliosphere. We found that polar solar winds become highly anisotropic at the Cycle 24/25 minimum, which is a peculiar aspect of this minimum. The IPS observations showed general agreement with the Parker Solar Probe observations around the perihelion of Orbit 1; this supports the reliability of the CAT analysis. The results of this study suggest that the physical properties of solar wind microturbulence may vary with a long-term decline in the solar activity, which provides important implication on the solar wind acceleration.

Innovatory role of nanomaterials as bio-tools for treatment of cancer

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Khuram Shahzad Ahmad ◽  
Muntaha Talat ◽  
Shaan Bibi Jaffri ◽  
Neelofer Shaheen
Keyword(s):  
Cancer Treatment ◽  
Cancer Therapeutics ◽  
Physicochemical Characteristics ◽  
Global Scale ◽  
Current Review ◽  
Anti Cancer ◽  
Different Types ◽  
Cancerous Cells

AbstractConventional treatment modes like chemotherapy, thermal and radiations aimed at cancerous cells eradication are marked by destruction pointing the employment of nanomaterials as sustainable and auspicious materials for saving human lives. Cancer has been deemed as the second leading cause of death on a global scale. Nanomaterials employment in cancer treatment is based on the utilization of their inherent physicochemical characteristics in addition to their modification for using as nano-carriers and nano-vehicles eluted with anti-cancer drugs. Current work has reviewed the significant role of different types of nanomaterials in cancer therapeutics and diagnostics in a systematic way. Compilation of review has been done by analyzing voluminous investigations employing ERIC, MEDLINE, NHS Evidence and Web of Science databases. Search engines used were Google scholar, Jstore and PubMed. Current review is suggestive of the remarkable performance of nanomaterials making them candidates for cancer treatment for substitution of destructive treatment modes through investigation of their physicochemical characteristics, utilization outputs and long term impacts in patients.

scholarly journals Broken Worlds: Towards an Archaeology of the Shatter Zone

2021 ◽  
Author(s):  
Ben Raffield
Keyword(s):  
Eighteenth Century ◽  
Global Scale ◽  
Physical Geography ◽  
Trigger Factors ◽  
Eastern Woodlands ◽  
Term Change ◽  
Anthropological Research ◽  
Historic Change

AbstractIn recent years, archaeological studies of long-term change and transformation in the human past have often been dominated by the discussion of dichotomous processes of ‘collapse’ and ‘resilience’. These discussions are frequently framed in relatively narrow terms dictated by specialist interests that place an emphasis on the role of single ‘trigger’ factors as motors for historic change. In order to address this issue, in this article I propose that the study of the ‘shatter zone’—a term with origins in physical geography and geopolitics that has been more recently harnessed in anthropological research—has the potential to facilitate multi-scalar, interdisciplinary analyses of the ways in which major historical changes unfold across both space and time, at local, regional, and inter-regional levels. This article unpacks the concept of the shatter zone and aligns this with existing archaeological frameworks for the study of long-term adaptive change. I then situate these arguments within the context of recent studies of colonial interaction and conflict in the Eastern Woodlands of North America during the sixteenth to eighteenth century. The study demonstrates how a more regulated approach to the shatter zone has the potential to yield new insights on the ways in which populations mitigate and react to instability and change while also facilitating comparative studies of these processes on a broader, global scale.

scholarly journals Two decades of in-situ temperature measurements in the upper troposphere and lowermost stratosphere from IAGOS long-term routine observation

2017 ◽  
Author(s):  
Florian Berkes ◽  
Patrick Neis ◽  
Martin G. Schultz ◽  
Ulrich Bundke ◽  
Susanne Rohs ◽  
...  
Keyword(s):  
Weather Forecast ◽  
Global Scale ◽  
Temperature Trend ◽  
Data Set ◽  
Medium Range Weather Forecast ◽  
Upper Troposphere ◽  
Temperature Trends ◽  
Geographical Regions

Abstract. Despite several studies on temperature trends in the tropopause region, a comprehensive understanding of the evolution of temperatures in this climate-sensitive region of the atmosphere remains elusive. Here we present a unique global-scale, long-term data set of high-resolution in-situ temperature data measured aboard passenger aircraft within the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System, www.iagos.org). This data set is used to investigate temperature trends within the global upper troposphere and lowermost stratosphere (UTLS) for the period 1995 to 2012 in different geographical regions and vertical layers of the UTLS. The largest amount of observations is available over the North Atlantic. Here, a neutral temperature trend is found within the lowermost stratosphere. This contradicts the temperature trend in the European Centre for Medium Range Weather Forecast (ECMWF) ERA-Interim reanalysis, where a significant (95 % confidence) temperature increase of +0.56 K/decade is obtained. Differences between trends derived from observations and reanalysis data can be traced back to changes in the temperature bias between observation and model data over the studied period. This study demonstrates the value of the IAGOS temperature observations as anchor point for the evaluation of reanalyses and its suitability for independent trend analyses.

scholarly journals Mediterranean Sea climatic indices: monitoring long term variability and climate changes

2018 ◽  
Author(s):  
Athanasia Iona ◽  
Athanasios Theodorou ◽  
Sarantis Sofianos ◽  
Sylvain Watelet ◽  
Charles Troupin ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Mediterranean Sea ◽  
Climate Changes ◽  
Salt Content ◽  
Climatic Indices ◽  
In Situ Observations ◽  
The Mediterranean

Abstract. We present a new product composed of a set of thermohaline climatic indices from 1950 to 2015 for the Mediterranean Sea such as decadal temperature and salinity anomalies, their mean values over selected depths, decadal ocean heat and salt content anomalies at selected depth layers as well as their long times series. It is produced from a new high-resolution climatology of temperature and salinity on a 1/8° regular grid based on historical high quality in situ observations. Ocean heat and salt content differences between 1980–2015 and 1950–1979 are compared for evaluation of the climate shift in the Mediterranean Sea. The spatial patterns of heat and salt content shifts demonstrate in greater detail than ever before that the climate changes differently in the several regions of the basin. Long time series of heat and salt content for the period 1950 to 2015 are also provided which indicate that in the Mediterranean Sea there is a net mean volume warming and salting since 1950 with acceleration during the last two decades. The time series also show that the ocean heat content seems to fluctuate on a cycle of about 40 years and seems to follow the Atlantic Multidecadal Oscillation climate cycle indicating that the natural large scale atmospheric variability could be superimposed on to the warming trend. This product is an observations-based estimation of the Mediterranean climatic indices. It relies solely on spatially interpolated data produced from in-situ observations averaged over decades in order to smooth the decadal variability and reveal the long term trends with more accuracy. It can provide a valuable contribution to the modellers' community, next to the satellite-based products and serve as a baseline for the evaluation of climate-change model simulations contributing thus to a better understanding of the complex response of the Mediterranean Sea to the ongoing global climate change. The product is available here: https://doi.org/10.5281/zenodo.1210100.

scholarly journals Potential forMethanosarcinato contribute to uranium reduction during acetate-promoted groundwater bioremediation

2017 ◽  
Author(s):  
Dawn E Holmes ◽  
Roberto Orelana ◽  
Ludovic Giloteaux ◽  
Li-Ying Wang ◽  
Pravin Shrestha ◽  
...  
Keyword(s):  
Field Experiment ◽  
Electron Donor ◽  
Enrichment Culture ◽  
Cell Suspensions ◽  
Contaminated Groundwater ◽  
Subunit A ◽  
Sedimentary Environments

AbstractPrevious studies ofin situbioremediation of uranium-contaminated groundwater with acetate injections have focused on the role ofGeobacterspecies in U(VI) reduction because of a lack of other abundant known U(VI)-reducing microorganisms. Monitoring the levels of methyl CoM reductase subunit A (mcrA) transcripts during an acetate-injection field experiment demonstrated that acetoclastic methanogens from the genusMethanosarcinawere enriched after 40 days of acetate amendment. The increased abundance ofMethanosarcinacorresponded with an accumulation of methane in the groundwater. An enrichment culture dominated by aMethanosarcinaspecies with the sameMethanosarcina mcrAsequence that predominated in the field experiment could effectively convert acetate to methane. In order to determine whetherMethanosarcinaspecies could be participating in U(VI) reduction in the subsurface, cell suspensions ofM. barkeriwere incubated in the presence of U(VI) with acetate provided as the electron donor. U(VI) was reduced by metabolically activeM. barkericells, however, no U(VI) reduction was observed in inactive controls. These results demonstrate thatMethanosarcinaspecies could play an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth ofGeobacterspecies. The results also suggest thatMethanosarcinahave the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments.

scholarly journals Ecoacoustics: A Quantitative Approach to Investigate the Ecological Role of Environmental Sounds

Mathematics ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 21 ◽  
Author(s):  
Almo Farina
Keyword(s):  
Full Range ◽  
Individual Species ◽  
Ecological Role ◽  
Dissimilarity Index ◽  
Detection And Identification ◽  
Quantitative Metrics ◽  
Ecological Complexity

Ecoacoustics is a recent ecological discipline focusing on the ecological role of sounds. Sounds from the geophysical, biological, and anthropic environment represent important cues used by animals to navigate, communicate, and transform unknown environments in well-known habitats. Sounds are utilized to evaluate relevant ecological parameters adopted as proxies for biodiversity, environmental health, and human wellbeing assessment due to the availability of autonomous audio recorders and of quantitative metrics. Ecoacoustics is an important ecological tool to establish an innovative biosemiotic narrative to ensure a strategic connection between nature and humanity, to help in-situ field and remote-sensing surveys, and to develop long-term monitoring programs. Acoustic entropy, acoustic richness, acoustic dissimilarity index, acoustic complexity indices (ACItf and ACIft and their evenness), normalized difference soundscape index, ecoacoustic event detection and identification routine, and their fractal structure are some of the most popular indices successfully applied in ecoacoustics. Ecoacoustics offers great opportunities to investigate ecological complexity across a full range of operational scales (from individual species to landscapes), but requires an implementation of its foundations and of quantitative metrics to ameliorate its competency on physical, biological, and anthropic sonic contexts.

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